package com.sai.common.utils;


import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletResponse;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.util.Random;

/**
 * 图片生成器
 *
 */
@Component
public class RandomCodeUtil {
    /**
     * 随机产生数字与字母组合的字符串
     */
    private String randString = "3456789ABCDEFGHJKLMNPQRSTUVWXYZ";
    /**
     * 图片宽
     */
    private int width = 150;
    /**
     * 图片高
     */
    private int height = 36;
    /**
     * 干扰线数量
     */
    private int lineSize = 40;
    /**
     * 随机产生字符数量
     */
    private int stringNum = 4;

    /**
     * 颜色
     */
    private int coloer = 255;

    private static final Logger logger = LoggerFactory.getLogger(RandomCodeUtil.class);

    private Random random = new Random();

    /**
     * 获得字体
     */
    private Font getFont() {
        return new Font("Georgia", Font.CENTER_BASELINE, 32);
    }

    /**
     * 获得颜色
     */
    private Color getRandColor(int fc, int bc) {
        if (fc > coloer) {
            fc = 255;
        }
        if (bc > coloer) {
            bc = 255;
        }
        int r = fc + random.nextInt(bc - fc - 16);
        int g = fc + random.nextInt(bc - fc - 14);
        int b = fc + random.nextInt(bc - fc - 18);
        return new Color(r, g, b);
    }

    /**
     * 获取验证码
     *
     * @return
     */
    public String randomCode() {
        StringBuffer randomCode = new StringBuffer();
        for (int i = 1; i <= stringNum; i++) {
            randomCode.append(randString.charAt(random.nextInt(randString.length())));
        }
        return randomCode.toString();
    }

    /**
     * 生成随机图片
     */
    public void generateCaptcha(String randomCode, HttpServletResponse response) {
        // BufferedImage类是具有缓冲区的Image类,Image类是用于描述图像信息的类
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        // 产生Image对象的Graphics对象,改对象可以在图像上进行各种绘制操作
        Graphics g = image.getGraphics();
        // 图片大小
        g.fillRect(0, 0, width, height);
        // 字体大小
        g.setFont(getFont());
        // 字体颜色
        g.setColor(getRandColor(110, 133));
        // 绘制干扰线
        for (int i = 0; i <= lineSize; i++) {
            drowLine(g);
        }
        for (int i = 1; i <= stringNum; i++) {
            drowString(g, randomCode.charAt(i - 1), i);
        }
        g.dispose();
        try {
            // 将内存中的图片通过流动形式输出到客户端
            ImageIO.write(image, "png", response.getOutputStream());
        } catch (Exception e) {
            logger.error("将内存中的图片通过流动形式输出到客户端失败>>>> ", e);
        }
    }

    /**
     * 绘制字符串
     */
    private void drowString(Graphics g, char code, int i) {
        g.setFont(getFont());
        g.setColor(new Color(random.nextInt(101), random.nextInt(111), random.nextInt(121)));
        g.translate(random.nextInt(3), random.nextInt(3));
        // 字符 左边距 上边距
        g.drawString(String.valueOf(code), 25 * i, 28);
    }

    /**
     * 绘制干扰线
     */
    private void drowLine(Graphics g) {
        int x = random.nextInt(width);
        int y = random.nextInt(height);
        int xl = random.nextInt(13);
        int yl = random.nextInt(15);
        g.drawLine(x, y, x + xl, y + yl);
    }

    /**
     * 获取随机的字符
     */
    public String getRandomString(int num) {
        return String.valueOf(randString.charAt(num));
    }
}
